The present invention relates to a telephone system and in particular to a versatile universal single phone system integrating the attributes of an external Central Office line system and of an interior secondary phone system.
As those who have lived in a tenement or an apartment house are fully aware, two phone systems are generally provided. The first is the ordinary and conventional telephone system tied to the telephone company Central Office by which the subscriber can obtain a line connected to anyone in any location in the world who has a similar line. The second system provides the subscriber with the ability to communicate, with the some difficulty, with certain of his or her neighbors within the local complex, the building guard, the doorman, or the building manager.
It is both an inconvenience and an annoyance to have two phones in one's apartment, each serving a different need. It is also expensive, as one must subscribe to the commercial phone system, and also pay for the separate intercom system.
Attempts have been made to overcome these disadvantages by providing highly complex systems through the dialing of various codes in order to provide communication within a building or apartment complex. Such systems are commonly found in large hotels, offices, or complexes, where the cost of the phone system is only a relatively minor factor. In addition to the added costs, such systems are not truly versatile as intercom calls are possible only through the use of increasingly complex dialing codes and excessive tolls. In these systems separate phone numbers are required. More importantly, these systems sacrifice such functions as call waiting, hold, redialing, and the like now common in commercial phone systems, in order to make room for the intercom functions.
It is an object of the present invention to provide an integrated system by which both outside commercial phoning via a Central Office (CO) and interior intercom calls can be readily made.
It is a further object of the present invention to provide a "one phone" system in which PBX intercom, or auxilliary CO calls can be superimposed without interference with the Central Office functions and without extra fee.
It is a further object of the present invention to provide a "one phone" combined CO and intercom system having none of the disadvantages of the conventional two phone systems.
More importantly, however, it is an object of the present invention to provide a system which in no way effects the commercial or CO system and may be installed via any registered and permissible jack or connection to a Central Office terminal without additional interface or modification of any Central Office system.
The foregoing objects together with numerous other objects and advantages will be apparent from the following disclosure of the present invention.